Monsoon over in Bihar, winter to set in from November 10

PATNA: The rain that played a spoilsport on Saptami and Ashtami of Navaratra was probably the last of this monsoon season in Bihar as India Meteorological Department (IMD) on Saturday claimed that rain-bearing winds have withdrawn.
Southwest monsoon bid adieu to the state with just 5% rainfall deficiency, making this year's rainfall highest in the past five years. The monsoon retreat has also paved the way for the onset of the crisp weather in Bihar, which is expected post-Chhath (around November 10).
As per the IMD weather bulletin, the monsoon withdrawal line passed through Darbhanga and Gaya Friday morning and Forbesganj in the afternoon.
It forecast a dry weather over the next five days.
Weathermen primarily consider three indicators for withdrawal of monsoon - gradual plunge in rainfall, change in the wind direction and fall in relative humidity. "As the rainfall stops, it leads to plunge in relative humidity. Already, there is a wind reversal from moist easterly to dry westerly," said Arpita Rastogi, a Met scientist at Patna meteorological centre.
The rain-bearing winds had entered Bihar on June 17, late by seven days of the normal onset date. The four-month-long monsoon season (June-September) concluded on September 30. As per IMD norms, eight districts received normal rainfall (+/-19 %) and only Gaya and Kishanganj received surplus rainfall (more than 19% of normal average rainfall) during this monsoon.
With monsoon winds gone, winter season is gradually approaching the state and a nip in the air is being felt by residents in the late night hours. Weathermen claim winter season is expected to set in Bihar around November 10.
"Though we do not make an official declaration for the onset of winter, weather conditions for the same are expected to be met around November 10," said Arpita.
As a thumb rule, the weathermen consider it winter when the minimum temperature is 13 degrees C or below. Winter season had set in at Patna on November 18 last year and it was around the first week of December in 2014 and 2013.
"This is the transition period as we are approaching winter season. Thus, there would be frequent variations in day as well as night temperatures," said Arpita.
Health experts have also cautioned residents to take preventive measures for tackling frequent temperature variations. "Frequent variations in temperature stimulate viruses, which leads to viral diseases like fever and flu. Thus, people should cover their mouth and nose from handkerchief or towel, while coughing and sneezing. Besides, people should avoid airconditioner or cooler while sleeping in the night. Moreover, special attention should be given to the health of children and senior citizens during this period," said Dr Diwakar Tejaswi.